Abstract: A device for testing continuity and current leakage at leads of an electronic circuit such as an integrated circuit has a contact structure (16) having test terminals (T1-T28) for contacting the leads. A first and a second of the leads are power supply leads respectively contactable with a first and a second of the test terminals (T14 and T28 or T26). Continuity/leakage detection is done with one or more corresponding detection circuits (D1-D28). Each detection circuit has a channel along which both continuity and leakage are tested. A supply switching circuit (26) appropriately switches voltages between values suitable for continuity testing and values suitable for leakage testing.
Abstract: The disclosed apparatus for determining the acceleration induced changes in the electrical characteristics of a quartz crystal includes all the apparatus necessary for subjecting the crystal to random acceleration forces and simultaneously determining the electrical characteristics of the crystal. More specifically a vibration generator is provided to subject the crystal under test to random vibrations of a predetermined acceleration. A low noise signal generator provides a signal at the resonant frequency of the crystal. The crystal couples the output of the low noise signal generator to a phase detector to determine the phase shift of the crystal. The output signal of the phase shift detector is analyzed to determine the acceleration versus electrical characteristics of the crystal under test.
Abstract: For use with a wiring system having a plurality of wires, a control device having a detector having a plurality of actuatable, observable parts which are numbered, and an electrical circuit coupled with the detector for actuating a specific numbered part thereof when a lead of the circuit is coupled to a particular wire. The apparatus is especially suitable for use in wiring system in which a plurality of wires extend from respective remote stations to a central station. In one embodiment, numbered resistance modules are coupled to the wires at respective remote locations to assign numbers to the wires, and the control device is at the central station for identifying the wires at the central station by successive actuation of the numbered parts of the detector unit. In a second embodiment, a resistance block is coupled to the wires at the central station to assign numbers to the wires, and the control device is used at the remote stations to identify the wires at such remote stations.
Abstract: A motor speed detector employs a magnetic sensor for detecting rotational movement of rotor armature segments of the motor and for producing real tachometer pulses in response to such movement. False tachometer pulses produced by extraneous non-rotor motor components are discriminated against to produce a signal representative of actual motor rotational speed.
Abstract: A method of testing the impedance of an IMPATT diode operating as a pulsed oscillator at a predetermined pulse repetition frequency is shown to comprise the steps of alternately applying through different, but known, paths, a test signal to the bias line to such diode and observing the change in the test signal as reflected from the IMPATT diode.
June 18, 1984
Date of Patent:
March 11, 1986
Lawrence H. Olsen, Donald S. Porterfield
Abstract: An apparatus for measuring the speed of a projectile fired from a handgun or small arm has a measuring path, over which the projectile passes, with light gates disposed spaced apart from one another. Each light gate has a light responsive element, which is shielded from the projectile path by a screen containing a light admitting aperture. An electronic signal evaluation circuit processes the signals emitted by the two light responsive elements in accordance with the darkening of the apertures caused by the projectile in flight above them and supplies these signals to a display device. In order to reduce to a minimum the danger of damage to the apparatus or of harm to persons, caused either by the projectile itself or by parts broken off the apparatus by the projectile without providing a connection between the barrel of the gun and the measuring apparatus, the arrangement is selected such that the two light responsive elements are disposed behind a separating wall common to both.
Abstract: A coil sensor excited with alternating current and connected in a circuit for detecting changes in the coil impedance producing a signal exceeding a fixed threshold value in response to the revolution of a wheel with features providing periodic changes in the spacing between the coil and the wheel, has its periphery subdivided into zones where the surface material is alternately thereomagnetic and non-theromagnetic. With a suitable setting of the frequency of the exciting alternating current and a suitable choice of the materials with respect to their eddy current and magnetic induction effect on the inductance of the coil, it is possible to suppress the signal of once per revolution periodicity resulting from wheel eccentricity, bearing wobble or the like.
Abstract: A method of quantitatively measuring the relative alignment of elements on a surface of a semiconductor body formed by two sequential masking steps during processing is provided. A fixed pattern of rectangular images are formed on a first mask; and a fixed pattern of repeating U-shaped images are formed on a second mask. The semiconductor body is processed so that the rectangular images on the first mask align with the U-shaped images on the second mask. An electrical probe is applied to opposed ends of the boustrophederal pattern formed and the electrical resistance measured to determine a parameter related to the relative alignment of elements on the semiconductor body.
Abstract: A method of continuously and uniformly examining a semiconductor shield of an electrical cable. The method includes the step of providing a cavity structure capable of supporting a relatively high order coaxial mode of microwave energy at a relatively high quality factor when the cavity is dielectrically unloaded. Microwave energy is directed to the cavity in a manner that excites the high order mode, and a cable having a semiconductor shield is continuously directed through the cavity structure. The semiconductive material loads the cavity structure and thereby changes the quality factor thereof. The loading of the structure and the changing quality factor thereof are continuously monitored to provide an indication of changes in the integrity of the semiconductive shield.
Abstract: A modular field strength measuring and indicating instrument that includes as one component a sensing module with a sensitive D'Arsonval meter movement and a receptacle for interchangeable plug-in type sensing modules for measuring an electrical condition, such as electrical power. The other component is a field strength sensing module that plugs into the receptacle and which includes a self-contained DC voltage source, a sensing antenna, a high-impedance, variable gain, linear DC amplifier operatively connected to the voltage source for amplifying the field strength voltage signal sensed by the antenna, and circuitry for transmitting the amplifier output voltage signal to the D'Arsonval meter movement for indicating the field strength detected by the instrument. The field strength sensing module may be used in the meter module interchangeable with other modules, such as modules for measuring RF power in RF transmission lines.
Abstract: An instrument for measuring electrical resistance or reactance comprises a sine wave generator which generates an a.c. signal and reference signals for a phase sensitive detector. The a.c. signal is applied to a decade attenuator which adjusts its amplitude in dependence on a range switching. The signal is passed to a bridge section, wherein it is applied to a component to measure the value thereof. A voltage output, indicative of the value, is fed to a gain block, wherein its amplitude is re-adjusted in dependence on an input from the range switching. The voltage output is operated on by a phase sensitive detector and passes to a digital display. In the reactance mode, set by a function switching, the a.c. signal is phase shifted before being applied to the component, so that the voltage output is in phase with the reference signals.
Abstract: A capacitive probe assembly is comprised of an electrode subassembly and an electric circuit subassembly which can be readily connected to and disconnected from each other, both mechanically and electrically. The electrode subassembly comprises a measuring electrode and a guard electrode concentrically mounted within a tubular, electrically conductive housing while being insulated from each other and from the housing. The measuring and guard electrodes are exposed through one of the opposite open ends of the housing. Inserted in the housing through the other open end thereof, the circuit subassembly includes a circuit board, with measuring circuit elements mounted thereon, which is supported at one end by a plug and at another end by a disclike support. The plug is engaged in sockets in the measuring and guard electrodes for both mechanical and electrical connection of the measuring circuit board to the electrodes.
Abstract: Measurements of yarn denier using capacitance transducers are automatically corrected for moisture. Samples of the yarn to be run are tested at different moisture levels at different frequencies in each of two capacitance transducers. The difference in the apparent denier outputs of the two transducers has been found to be proportional to moisture content. The difference is added to one of the measured values to provide a more correct reading. The difference may be further corrected by a factor derived from the slopes of the curves of transducer output vs. moisture and the slope of the curve of skein denier vs. moisture.
Abstract: The invention concerns a method of direct measurement of a parameter characterizing a fault on an electricity line 1, such as the distance x or the resistance R.sub.d of the fault, the method being based on Ohm's Law including the line inductance L and the resistances R, R.sub.d. The signals respectively associated with the variation of current i(t) and of voltage v(t) at the measuring point M are operated upon by transfer functions the ratio of which is equal to:(2/.tau.) tan .omega..tau./2,.tau. corresponding to the propagation time of a wave over double the distance between the measuring point M and a zone boundary P. The method thus takes into account the distributed capacitances C of the line.
Abstract: A first sensor for the detection of dielectric failure (by burning) within a multilayer printed circuit assembly comprises an isolated conductive layer. This first sensor is connected by a first diode to a single wire which also connects a second, temperature, sensor via a second diode (system ground is a return). A multiplicity, nominally 16, of such single wire connected sensor pairs are selectable in accordance with an externally (microprocessor) furnished address. During a first time period, an externally (microprocessor) selected interrogation of temperature causes a first, positive, voltage bias to be applied to the selected sensor pair resulting in a current linear with temperature (over the range of 0.degree. C. to 100.degree. C.) in the second sensor. This current is transformed to voltage, offset by 273.degree. Kelvin, amplified, and converted to a digital value for issuance to an external (microprocessor) requestor.
Abstract: A method of non-destructively identifying different kinds of rolled steel for structural purposes is disclosed, which is based on a synchronous detection process using a minute AC signal current. Four terminal probes arranged in a row and spaced apart at a precisely uniform pitch are held urged against a measuring surface of steel under test. The signal current is passed through the steel via the opposite end terminal probes. A potential difference is detected between the other two terminal probes. A resistivity corresponding to the detected potential difference is determined, and a corresponding value of silicon content in the steel is determined. The kind of steel is identified according to the determined silicon content.
Abstract: In an analog display device, a pointer (1) can be reset by a stepping motor (2) which receives a constant number of pulses upon a reset command. In this way, starting from any position, the pointer is certain to reach the stop which corresponds to its zero position. In order in this connection to keep the mechanical force on the stop (6) and the transmission elements (3 and 4) between the pointer and the stepping motor small, the pulses for the resetting are produced initially with a relatively low pulse frequency and then with a higher pulse frequency. As a result, the stepping motor starts up reliably with a relatively high driving torque but gives off only a smaller driving torque when the stop in the zero position is reached.
Abstract: A system for monitoring the integrity of a cable, for example a cable for towing a variable depth sonar body through the ocean, is described. Such a cable comprises a core of electrical wires surrounded by load bearing wires which are secured to the sonar body through a terminator. For various reasons cracks can appear in the load bearing wires and in extreme cases one or more of the wires may break. The monitoring system includes a transducer located near the terminator where the wires are most likely to crack or break and acoustic emissions caused by the incidence of cracks or breaks are picked up by the transducer. The resulting electrical signals are amplified and passed up the electrical core of the cable to the towing vessel where they are processed. Novel aspects of the system are the water coupling between the location of the cracks or breaks and the transducer and special processing circuitry which enables breaks, cracks and electrical noise to be distinguished from each other.
October 11, 1983
Date of Patent:
January 21, 1986
Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence of Her Majesty's Canadian Government
James R. Matthews, George K. Schattschneider, Mervin R. Black, James A. Perkins
Abstract: There is provided a method and apparatus for locating leaks in flat roofs, particularly in flat roofs covered with a gravel layer, plants or the like, and wherein it is provided that a moisture location discovered below the flat roof is connected with a positive terminal of a pulse generator, the negative terminal of the pulse generator being connected with a metallic gutter edge of the flat roof, and the flat roof being scanned by measurement sensors for the purpose of measuring the pulses passing through the moisture path to the corresponding leak location and from the leak location through the moist, flat roof. The measurement sensors are connected with a measurement device for measuring the impulse amplitudes, which become successively weaker as they progress from the leak location to the rim of the flat roof.
Abstract: A method and apparatus for testing circuit boards using two or a small number of probes for making resistive and radio frequency impedance measurements e.g. capacitive measurements. The combination of resistive and impedance measurements substantially reduces the number of tests required to verify the integrity of a circuit board. The impedance or capacitive "norm" values used in testing the circuit boards can be obtained by operating the system in a learning mode. Analysis of the data provides not only fault detection but also can indicate approximate fault location.
March 7, 1983
Date of Patent:
January 21, 1986
Kollmorgen Technologies Corporation
Robert P. Burr, Raymond J. Keogh, Ronald Morino, Jonathan C. Crowell, James B. Burr, James C. Christophersen